请教GWD7-3

liufeng881025

Because of wireless service costs plummeting in the last year, and as mobile phones are increasingly common, many people now using their mobile phones to make calls across a wide region at night and on weekends, when numerous wireless companies provide unlimited airtime for a relatively small monthly fee.

A.Because of wireless service costs plummeting in the last year, and as mobile phones are increasingly common, many people

B.As the cost of wireless service plummeted in the last year and as mobile phones became increasingly common, many people

C.In the last year, with the cost of wireless service plummeting, and mobile phones have become increasingly common, there are many people

D.With the cost of wireless service plummeting in the last year and mobile phones becoming increasingly common, many people are

E.While the cost of wireless service has plummeted in the last year and mobile phones are increasingly common, many people are

答案是D，为什么D比E好呢？我觉得这个2个句子 and 两边也不平行啊。如果B选项改成 many people are 那是不是B就是最好的呢？

云南

while 改变句意了，原文不是转折关系

evilleo

我觉得E选项里and两边不平行。B选项我觉得increasingly说明状态的持续性，不应该用一般过去时态（只是个人见解）。我排除B的原因是因为缺少谓语，实际上我开始也差点选第二个答案的。